Spiral grinding machine



April 11, 1950 A. A. TOBIAS SPIRAL GRINDING MACHINE 2 sheets-sheet 1 Filed April 28, 1945- u r/ znvf. 75 ads A. A. ToBlAs SPIRAL GRINDING MACHINE April 11, 1 950 2 Sheets-Shet 2 Filed April 28, 1945 ml i]\ I I MN w w ffam e3 Patented Apr. 11, 195i SPIRAL GRINDING MACHINE Arthur A. Tobias, Chicago, Ill., assignor to Raymond T. Moloney, Chicago, Ill.

Application April 28, 1945, Serial No. 590,766

14 Claims.

1 This invention pertains to metalworking machines and has as its principal object the provision of a simple and compact spiral grinding and cutting head characterized by small size, simplicity of construction, operation, and maintenance, and adaptability for use in various types of milling and grinding machines, and the like.

More particularly, it is an object of the invention to provide a machine for holding tools or stock for grinding, milling, thread, cam, and gear cutting, or the like, and adapted to give to the tool or stock any desired pitch or lead in relation to a grinding, cutting, or dressing tool.

A further object is the provision of a device of the class described consisting of a work holder arranged for both rotative and axial displacement, and adjustable means supporting and securing the work holder for such movement at de sired angles of lead and pitch, as well as means for releasing the adjustable supporting and securing means so that the work holder may be freely moved in both or either of its degrees of motion.

A further object is the provision of a device of the class described in which the work holder is supported by a plurality of bearings having individual axes of movement which may be set at a desired angle to the axis of the work holder, thereby causing the latter to describe a spiral movement when an operating torque is applied thereto.

Still another object is the provision of a rugged, dustproof, but simple housing for the supporting and motion-governing bearings for the workholder.

Yet another object is the provision, in a device 'of the class described, of a plurality of bearings and adjustable holders therefor removably secured in a headstock on substantially opposite sides of a workholder spindle such that the latter 'will be displaced in a spiral motion, the pitch and lead of which will be determined by the setting of said bearings, when an operating force is applied manually, or otherwise, to the work- 'holder.

Additional objects, advantages, and aspects of "novelty and utility relate to details of construc- "tion and operation of the illustrative embodiment described hereinafter in view of the annexed drawings, in which:

Fig. 1 is a perspective view of the complete machine Fig. 2 is a side elevation, partly in section of the same;

Fig. 3 is a cross section along lines '3--3 of 2 Fig. 2 showing one pair of spindle bearings in elevation;

Fig. 4 is a cross section along lines 44 of Fig. 2 showing parts of the upper releasable bearing in elevation;

Fig. 5 is a top plan fragment of the headstock showing the releasable bearing control;

Fig. 6 is a cross section along lines 6-6 of Fig. 2 showing the index stop in elevation;

Fig. 7 is a cross section along lines l'l of Fig. 2 showing the movable index member on the collet;

Fig. 8 is a perspective detail to enlarged scale of one of the bearing mounts;

Fig. 9 is a schematic illustration of the pitchedbearing array for effecting spiral motion of the workholder spindle.

Referring to Fig. 1, the novel grinding machine consists of a base plate [5, adapted to fit into the bed of a milling machine or the like. A pair of uprights or trunnion posts l6 and I! are secured to this base plate, and each post has a split top section [6a and Ha. respectively, as in Fig. 6, and Fig. 2, and serving to clamp the head'- stock casing IS in position, the latter having reduced end portions l8a, [8b, as in Fig. 2, which are clamped between the main post portions l6 and I! and their respective top sections 16a and I la, as aforesaid.

By preference, the headstock casing is of peculiar contour, as apparent particularly in the cross section of Fig. 3, this contour being basically cylindrical with longitudinally-extending and circumferentially spaced fiatted sections 20 separated by intervening cylindrical sections 2|, the flatted sections being especially suited to the mounting and accessibility of the bearing units, hereinafter described.

At the forward end of the machine, as in Fig. 1, there is provided a conventional collet 25, which fits into a tubular bore 26 in the spindle 21 (Fig. 2, also), this bore terminating in an enlarged end threaded to receive theusual threaded chuck collar 28, while the opposite end of the spindle has secured thereto a knurled cylindrical handle element 29.

As viewed in Figs. 2 and 6, theiorward end of the spindle is sealed off against emery dust and cutting and grinding particles by a felt or similar washer 3| seated in an annular recess in an index collar 32 having a stopping projection 33 which is adapted to be engaged by any one of four stop lugs or projections 34 (Fig. '7) formed on a stop ring 35 bolted as at 36 to the enlarged end portion of the spindle, the disposition and spacing of these stop lugs 34 being such that, as the spindle is rotatively retracted, one of the lugs will strike home against the fixed stepping projection 33, which one, depending upon the starting position from which the spindle was initially moved, as will be more particularly described hereinafter. The annulus 32 upon which the stopping projection 33 is based is secured to the post l6 as by recessed bolts 33o, Fig. 6.

Forward .or .axial displacement of the spindle may be limited as desired by loosening set screw 30a on a stop collar 30 at the handle end of the spindle, Fig. 2, and resetting the screw.

An important feature of the invention is the use of bearing means to control and effect spiral motion of the workholder spindle. This feature is illustrated schematically in Fig. ,9, wherein the spindle 2'1 is shown fragmentally, the view being such that the observer is looking down at the top of the spindle. Firmly engaging the periphery of the spindle .on opposite. sides thereof and at ,a level below the center of the spindle along its length, are a plurality of ball bearings A, B, C, andD, all having their axes :of rotation pitched relative to the longitudinal axis of the spindle. A releasable holding bearing E, likewise pitched, presses down on the top of the spindle 27 and forcing the latter into driving engagement with the spiraling bearings A, B, C, D, the construction being such that if the holding bearing E be released, the spindle 2.1 may be shifted axially, or

rotated, at will.

The mounting of the several bearing elements is readily understood frcm the illustrations of Figs. .2 and 8, with particular regard to the holding bearing. As in Fig. 2, .a block 4t (shown in perspective in Fig. 8) is fitted into a recess formed in the upper flatted portion 210 :of the housing (see also .Fig. l) and an annular insert M (Figs. 2 and is fitted into a well formed in the block 40; this insert has a central socket 42 to receive .a conventional Hex. wrench by which the insert may be rotated in the well provided a pair of socket-headed setting bolts 43 are first loosened.

Block 4.0 .is loosely fitted into its seat in the top z .of the housingso that it may rock on a pintle rod .44 drivingly seated in the housing (Fig. 5). On the undersideofblock 48 (Fig. .8) are a plurality of spring wells 45 in which are. disposed springs 45. (Fig. 2 normally rocking the block 40 so as to thrust aholding bearing E down on the spindle 2,1 for the purposes hereinbefore alluded to. The manner vof mounting the holding bearing E is shown in Fig. 8, wherein appears a post projection 41a of the insert 41, which post is cut away, as at 41b toprovide asurface lOIl which is mounted the holding bearing E. The outer face of the insert 4| is calibrated, as suggested at 48, Fig. 5, foraccurate setting of the pitch of the holding bearingE, that is, its-angular relation to the axis of thespindle.

In order to release the holding action of bearing E, there isprovided (Fig. 2) a release lever 50 pivoted on a pintle rod 5| driven into the housing block, and at one end this lever is provided with a thumb-plate '52 or handle portion, while at its opposite end, is a boss 53 engaging under an undercut in the block ill), the operation being such "that when-the thumb-plate is pushed downwardly, the end of plate 40 engaged lay-boss 53 is lifted against the actionof springs 46, thus lifting the bearing E from engagement with the spindle 21, thereby freeing thelatter for optional movement; upon release of the lever 5i], springs 46reseat the bearing E on the spindle.

The remaining bearing elements A, B, C, and D, described functionally in view of Fig. 9, are substantially identical to the bearing means E just described, excepting that these remaining bearing elements are not provided with mounting blocks such as the block all, since they are not ordinarily to be disengaged from the spindle, but only need be adjusted for angular setting relative thereto. Accordingly, as in Fig. .2, the bearing element B, for example, consists of an insert having a central adjusting-wrench socket 5| by which it is rotatively adjusted provided the corresponding set screws 62 are loosened, and this insert, likethat of Fig. 8, has an inwardly projecting post 63 (Fig. 3,) on which the ball bearing unit 13 is mounted, attention being called to the fact that the bearings B and D in Figs. 3 and 4 are not pitched as in Fig. 9, in order that the actual mounting construction may more clearly appear in Figs. 3 and 4.

The mounting and adjustment features of the remaining bearing units A, D, and C, are identical to those just described for bearing unit B and therefore need not be recited in detail. -As indicated in Fig. 2, .the outer face of the several inserts for bearings A, B, C, and D, is calibrated like the insert ll described for bearing unit .E, to facilitate accurate setting of the pitch and lead.

In the use of the novel device, asfor example (in backing oil a twist drill such as shown in the collet chuck in Figs, 1 and 2, the pitch and lead of the drill spiral is determined by measurement, and the several calibrated dial inserts, such as dial 4! and dial 6B of Fig. 2,.are set identically, preferabl by reference to a prepared table calculated for the various operations of which the device .is capable; thereafter the dials are set by tightening their respective setscrews, 43, 52, etc., whereupon the top or holding bearing E is released by depressing lever means 5il52 to free the spindle .so that the latter may be retracted and turned with the first index stop 34 (Fig. 7), which is marked 1," full against the stopping projection 33, as in Fig. 1, after which .the lever means 50-52 is released. and the device is ready for use, the same usually being set in the bed of a milling machine or grinder (not. shown) having, in this example, a grinding wheel 10 (Fig. 2) disposed to'be engagedby the Work or twist drilLas shown.

Assuming that the several bearing units A, B, C, D, and E of the novel grinding head have been properly set, as aforesaid, for the pitch and lead of the particular drill to be backed, the operator turns handle 29, and the spindle 21, by action of said bearingunits, will advance with a spiral motionand accurately iollo-w the spiraling of'the twistidrillsothat the edge-of thespiral .fiutes thereof will .progresively be presented to the grinding action of the wheel It. When the first, spiral of the drill .has been backed'ofl the full .extentof itslength, the handle 29 is turned in the reverse direction to retract the spindle andreleaselever flee-.52 is depressed, freeing the spindle again, whereupon the operator sets the next index, stop, 52 againstv thefixed stop33 to start the nextspiral. of the drill, and the handle .29 is again turned. to cause a spiraling advance of the twistdrill or work relative to the grinding wheel ill, to back oi the secondflute, and soon, .untilall of .the spiralsor ,fiutesaredressed. An index stop collar, 35, such as shown in Fig. 7, is adequate for .most operations; however, different collars may be provided for special operations, with steps 34 disposed. as required.

iseases The calibrations, e. g. 48, Fig. 5, are by preference arbitrarily chosen in compiling tables for various operations, the calibrations for the several units being identical to facilitate quick and accurate setting of the angularity of the bearings .for a given operation, it being important to observe that the calibrations for the scales of units on one side of the spindle, e. g. A and B, are reversed with respect to those of the units C and D on the opposite side of the spindle.

In the illustrative embodiment, there are three groups of bearings arranged about the periphery of the spindle, looking into the end of the spindle, as in Fig. 4 for example, and these groups are by preference spaced equidistantly apart, in the present instance, 120 degrees apart; however, it will be understood that this number and spacing is not critical and may be departed from. Ihe arrangement shown is very satisfactory for the described purposes.

It is pointed out that the shaft or spindle 2'! -is loosely fitted in the housing in order that it may be moved into and out of driving engagement with the several bearings or rotatable elements by manipulation of the releasable bearing.

E; and in this connection, the felt sealing washers 3| provide a relatively firm but yieldable seat for the spindle, while the several bearings provide the actual operating support therefor.

Having thus described my invention, it will appear that I have provided a spiral grinding head or fixture which is small, compact, simple and relatively inexpensive to build; which may be readily dismantled and assembled; in which the spiral-motion effecting means is a simple set of bearings having circumferentially spaced, peripheral, driving engagement with the main work spindle; which bearings are correlatively adjustable and effectively releasable from driving engagement with said spindle; in which the essential working parts are shielded from dust and grinding particles; in which indexing is quickly and accurately effected by means associated with the collet close to the work; and in which very fine or course degrees of pitch and lead may be p had at will. And while a preferred embodiment has been described herein in specific detail, such description is not intended to be limiting, excepting as may be expressly provided by the appended claims, namely:

1. A device of the class described comprising a spindle including a work holder, a plurality of rotatable bearings drivingly bearing against said spindle at predetermined points about its periphery and having their respective axes of rotation disposed angularly relative to the axis of said spindle, whereby to impart a spiral displacement to said spindle upon application of a turning force thereto.

2. A device of the class described comprising a spindle having a work holder associated there with, a plurality of rotatable bearing members drivingly engaging said spindle at points angularly displaced thereabout, at least one Of said bearing members being disposed on a side of said spindle opposite from the others and yieldingly urging said spindle into driving engagement with said others, said one oppositely disposed bearing member being releasable from urging action on said spindle, whereby to free the latter for motion at will from the action of all of said bearing members, said bearing members being rotatable in parallel planes oblique to the axis of said spindle when drivingly engaged with the spindle as aforesaid, for imparting a complex motion to said complex motion including angular and axial displacement.

3. The invention defined in claim 1 further characterized in that said bearings are mounted for adjusting movement to change the angular relationship of their axes relative to the axis of the spindle and thereby alter the pitch and lead of the spiral motion of said spindle.

4. A spiral grinding machine comprising an elongated housing, a spindle extending longitudinally through said housing and movable longitudinally and rotatively therein, and a plurality of rotatable members engaging peripheral portions of said spindle in said housing and adjustable to dispose their respective rotational axes at an angle to the longitudinal axis of the spindle, whereby to impart a spiral motion to the spindle when a torque is applied thereto, and work holding means on an end region of the spindle.

5. A spiral grinding head comprising an elongated housing, a spindle extending longitudinally through said housing and movable longitudinally and rotatively therein, a plurality of rotatable members mounted as inserts in side portions of said housing and engaging peripheral portions of said spindle in said housing, said inserts being angularly movable to dispose the respective rotational axes of the corresponding rotatable members at desired angles relative to the longitudinal axis of said spindle, and when angularly adjusted as aforesaid, imparting a spiral motion to the spindle upon application of a turning force thereto, and work holding means at an end of the spindle, exteriorly of the housing.

6. The invention defined in claim 4 further characterized in that at least one of said rotatable members is disposed on a side of the spindle remote from the remaining said rotatable members, and said one remotely disposed rotatable member is normally spring-urged into engagement with the spindle thereby urging the latter into operative engagement with the said remaining rotatable members, together with means for disengaging said one remotely disposed member from urging engagement with the spindle to free the latter for movement at will, whereby the spindle may be disposed in desired starting positions.

7. Spiral motion tool grinding head including a shaft, fixed bearing means near the ends of said shaft supporting the same for both rotative and axial movement, rotatable elements drivingly engaging the shaft at spaced intervals along substantially opposite sides thereof and having their respective axes of rotation pitched substantially identically in an oblique sense to the axis of the shaft, torque applied to said shaft causing rotative motion of said elements, said rotative motion causing axial displacement of the shaft, whereby the resultant motion of the shaft as aforesaid is spiral, and work-holding means at an end of said shaft.

8. Spiral motion grinding means as defined in claim 7 and further characterized in that at least one of said rotatable elements is yieldably engaged with said shaftand normally urges the latter into driving engagement with the remaining said rotatable elements, said yieldingly engaging one of the elements being disengageable from urging action on the shaft as aforesaid to free the shaft for motion independently of said rotatable elements, whereby the shaft may be set in desired positions for subsequent spiral motion under control of said rotatable elements part to the latter a spiral motion the pitch and lead of which may be selectively predetermined by adjustment of the aforesaid angularity adjusting means, and means for coupling said spindle with work.

10. In a spiral tool grinding device, a shaft, spaced bearing means supporting said shaft for rotation and longitudinal movement, said shaft adapted to have a turning force applied thereto; a plurality of rotatable elements drivingly engaging said shaft at points spaced circumferentially thereabout, at least one of said rotatable elements urging said shaft into driving engagement with the remaining said elements, means operable independently of said other rotatable elements for effectively disengaging said one of the rotatable elements from the shaft to free the latter from effective driving engagement with said rotatable elements, and means for adjusting the angularity of the rotative axes of all said rotatable elements relative to the axis of said shaft, whereby to selectively predetermi-ne the angular and axial displacements of said shaft responsive to the application of a turning force thereto.

11. In a spiral motion grinding and tool dress ing fixture, a shaft adapted to move spirally, a plurality of adjustable rotatable bearing members driving-1y engaging said shaft at points about its periphery and coacting with the shaft responsive to rotational motion thereof to impart lengthwise displacement thereto, fixed bearing means supporting said shaft loosely in operative relation as aforesaid to the adjustable bearing members, means including one of said bearing members yieldingly pressing said shaft into driving engagement with the remaining bearing members, and lever means operable independently of adiusting action of the other said hear-- ing members for relieving the action of said yielding'ly pressing means to free the shaft from effective driving engagement with said bearing members in order that the shaft may be set in a desired position.

12. A spiral grinding and cutting head comprising an elongated housing, a spindle passing lengthwise through said housing and supported by bearings at opposite ends of the housing for bothangular and linear movements, means at one end of said spindle for application of a turning efiort thereto, means at an opposite end of said spindle for coupling the same with work'to be displaced both angularly and linearly, a plurality of rollers normally drivingly engaging said spindle at spaced points all on one side of a diameter thereof, at least one presser roller .drivingly and pressingly engaging said spindle on the opposite side of said diameter to releasably urge the spindle into normal driving engagement with the other said rollers, manually actuated mechanism for relieving said presser roller from pressing engagement with the spindle to free the latter from all rollers for selective p0.- sitioning of the spindle, angularly and linearly, said rollers being adjustable to rotate in parallel planes each cutting the axis of the spindle at less than ninety degrees to cause linear movement of the spindle responsive to application of turning effort thereto, and index means for each roller for correlating the angular adjustments thereof as aforesaid.

13. In a spiral grinding fixture as defined in claim 9, stop means for indexing and comprising a fixed stop disposed radially adjacent said spindle, and a movable stop disposed radially of, and movably with, said spindle and further movable into abutment against said fixed stop responsive to combination rotative and axial motion of the spindle upon spiral-motion retraction of the latter into a predetermined starting position.

14. Stop means for indexing as defined in claim 13 and further characterized in that said means includes a plurality of said movable stops spaced circumferentially about said spindle, and said mechanism further characterized by the provision of means for freeing said spindle from said bearing means for displacement at will to dispose a selected one of said movable stops in a starting position in abutment with said fixed stop, whereby a plurality of spiral operations of the spindle may be selectively indexed.

ARTHUR A. 'IOBIAS.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,662,078 Severson Mar. 13, 1928 1,698,807 Willhauck Jan. 15, 1929 1,713,678 Sei-bert May 21, 1929 1,790,688 Koon Feb. 3, 1931 1,803,165 Booth Apr. 28., 1931 2,039,711 Einstein May 5, 1936 2325,36 1 Beeni-ng July 27, 1943 FOREIGN PATENTS Number Country Date 584,896 France Nov. 29, 1924 

